Safety-valve.



PATENTED FEB. 28, 1905.

A. ASHWORTH.

SAFETY VALVE. APPLICATION FILED JUNE 23,1903.

Invenfor M M Patented February 28, 1905.

PATENT OFFICE.

ARTHUR ASHWORTH, OF BURY, ENGLAND.

SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 783,407, dated February 28, 1905.

Application filed June 23, 1903. Serial No. 162,719.

To all whom it may concern:

Be it known that I, ARTHUR AsHwoR'rH, a subject of the King of Great Britain and Ireland, residing at Bury, in the county of Lancaster, England, haveinvented new and useful Improvements in Safety-Valves, of which the following is a specification.

This invention relates to the safety-valves of steam-generators; and its object is the utilization of the heat which is at present usually permitted to escape with the steam issuing when the valves are blowing ofl'T.

A safety-valve constructed or modified to embody my present improvements comprises two independent lift-valves, arranged one at the lower and the other at the upper end of a closed chamber, which is in communication through a valve or cock controlled pipe with any appliance in which the heat contained in the steam can be utilized. The lower valve is constructed to lift in the usual manner at the working pressure of the boiler and the upper valve at a little above the pressure in or on the appliance in which the heat is utilized.

My improvements are illustrated by the accompanying drawings, to which reference will hereinafter be made, and in which- Figure 1 represents a vertical section, and Fig. 2 a horizontal section along the line A B, Fig. 1.

The lower valve a may have the construction usually adopted and occupy the customary or any suitable and convenient position, and it may either be weighted orbe controlled, as shown, by a spring 8 in the ordinary. manner. Above it, either coaxially, as shown, or not, there is a second similar gravity or spring controlled lift-valve b. The lower valve a has its spring or its weight, as the case may be, adjusted to permit the valve to be lifted as soon as the working pressure of the boiler is exceeded. The upper valve 6 has its weight or spring so adjusted as to lift at a low pressure, as hereinafter described. The space between the valves (0 b is inclosed by a cylindrical or other metallic casing 0, adapted to withstand the low pressure which will exist within it when the valve is blowing off. This space communicates through a pipe 9 with an appliance in which the heat contained in the issuing steam can be used. This appliance may be any one of many various kinds. In the construction illustrated the valves (1/ I) have a common axis, and the upper end of the spindle of the valve a is axially bored to receive an under prolongation of the stem of the valve 6. The object of this is to permit the valve a when lifted to its full extent to forcibly lift the valve Z) and permit steam to escape into the atmosphere. If and when the heat in the escaping steam ceases to be utilized in the appliance to which it is conveyed by the pipe p, the valve or cook in that pipe can be closed either automatically by known devices or by hand, whereupon all the escaping steam will issue through the valve 5. The upper valve b need not be weighted to a pressure of from more than two to five pounds per square inch, as may be determined by the nature of the appliance in which the waste heat is to be utilized.

The upper part of the apparatus may be inclosed in a casing d, which is detachable and may or may not be normally secured, by a padlock or similar device. Within it there may be a perforated shield e to prevent access of dirt and foreign matters.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In a safety-valve, the combination with the working valve (0 of an auxiliary valve 6 lifting at a lower pressure, a working valvestem having an axial perforation at its upper end, an under extension of the auxiliary valvestem constructed to enter the said axial bore of the main valve-stem, a wall inclosing the space between the two valves, and a closable outlet p opening into the space between the two valves, substantially as and for the purpose set forth.

2. In a safety-valve, the combination with the working valve (0, of an auxiliary valve 6 lifting at a lower pressure, a Working valvestem having an axial perforation at its upper end, an under extension of the auxiliary valveto this specification in the presence of two substem constructed to enter the said axial bore of scribing witnesses.

the main valve-stem a Wall inclosing the space between the tWo vaives, and a closable outlet ARTHUR ASHWORTH 5 p, substantially as and for the purpose set Witnesses: forth. ERNALD SlMPsoN MOSELEY,

In testimony whereof I have signed my name MALCOLM SMETHURST. 

